STIMULATION OF PROTEOGLYCAN PRODUCTION BY GLUCOSAMINE SULFATE IN CHONDROCYTES ISOLATED FROM HUMAN OSTEOARTHRITIC ARTICULAR-CARTILAGE IN-VITRO

Objective: This study investigated the in-vitro effects of a crystalli ne glucosamine sulfate (GS) preparation on DNA synthesis and on proteo glycan (PG) and type II collagen (coll II) production by human articul ar chondrocytes isolated from human osteoarthritic articular cartilage in a 3-dimensional culture system for 4, 8, and 12 days. Materials an d Methods: Human articular chondrocytes from osteoarthritic femoral he ads were isolated from their matrix by collagenase digestion and then cultured in suspension. Under constant agitation, cells aggregated and formed a cluster within a few days. The effects of GS (1-100 mu g/ml) on chondrocytes were determined by quantifying DNA synthesis (by meas urement of [H-3]-thymidine uptake) as well as PG and coil II productio n using radioimmunoassays (RIAs) specific for coil II and to human hum an cartilage PG. Cross-reaction with GS in the RIAs was not detected. Moreover, PG size distribution was determined by exclusion chromatogra phy under associative conditions to determine the association of PG mo nomers with hyaluronic acid (HA) to form large molecular weight PG agg regates. Results: Under the above conditions, PCT production in cultur e media and chondrocyte clusters was increased by GS (10 100 mu g/ml). DNA synthesis and coil II production were not modified by GS. In addi tion, CTS did not modify the physico-chemical form of PG produced by c ells during culture. Conclusions: Glucosamine sulfate did not affect D NA synthesis nor coil II production but caused a statistically signifi cant stimulation of PG production by chondrocytes from human osteoarth ritic cartilage cultured for up to 12 days in 3-dimensional cultures.